}

  @CollectionFeature.Require({SUPPORTS_ADD, FAILS_FAST_ON_CONCURRENT_MODIFICATION})
  public void testSetCountZeroToOneConcurrentWithEntrySetIteration() {
    Iterator<Entry<E>> iterator = getMultiset().entrySet().iterator();
    assertSetCount(e3(), 1);
    assertThrows(ConcurrentModificationException.class, () -> iterator.next());
  }

    }

    @Override
    public boolean hasNext() {
      return !stack.isEmpty();
    }

    @Override
    public T next() {
      Iterator<T> itr = stack.getLast(); // throws NSEE if empty
      T result = checkNotNull(itr.next());
      if (!itr.hasNext()) {
        stack.removeLast();
      }
      Iterator<T> childItr = children(result).iterator();
      if (childItr.hasNext()) {

	if err == io.EOF {
		err = io.ErrUnexpectedEOF
	}
	r.err = err
	return r.current, err
}

// next will read one entry from the stream.
// Generally not recommended for fast operation.
func (r *metacacheReader) next() (metaCacheEntry, error) {
	r.checkInit()
	if r.err != nil {
		return metaCacheEntry{}, r.err
	}
	var m metaCacheEntry
	var err error

    assertEquals(ImmutableSet.of(), i.next());
    assertEquals(ImmutableSet.of(1), i.next());
    assertEquals(ImmutableSet.of(2), i.next());
    assertEquals(ImmutableSet.of(2, 1), i.next());
    assertEquals(ImmutableSet.of(3), i.next());
    assertEquals(ImmutableSet.of(3, 1), i.next());
    assertEquals(ImmutableSet.of(3, 2), i.next());
    assertEquals(ImmutableSet.of(3, 2, 1), i.next());
    assertFalse(i.hasNext());

    assertTrue(iterator.hasNext());
    assertEquals("1", iterator.next());
    assertTrue(iterator.hasNext());
    assertEquals("2", iterator.next());
    assertTrue(iterator.hasNext());
    assertEquals("3", iterator.next());
    assertTrue(iterator.hasNext());
    assertEquals("4", iterator.next());
    assertFalse(iterator.hasNext());
    try {
      iterator.next();
      fail("did not detect end of list");

    assertTrue(iterator.hasNext());
    assertEquals("1", iterator.next());
    assertTrue(iterator.hasNext());
    assertEquals("2", iterator.next());
    assertTrue(iterator.hasNext());
    assertEquals("3", iterator.next());
    assertTrue(iterator.hasNext());
    assertEquals("4", iterator.next());
    assertFalse(iterator.hasNext());
    try {
      iterator.next();
      fail("did not detect end of list");

    /**
     *
     */
    @Test
    public void test() {
        final SingleValueIterator<String> it = new SingleValueIterator<String>("Foo");
        assertThat(it.hasNext(), is(true));
        assertThat(it.next(), is("Foo"));
        assertThat(it.hasNext(), is(not(true)));
    }

        try {
          Event nextEvent;
          while ((nextEvent = queueForThread.poll()) != null) {
            while (nextEvent.subscribers.hasNext()) {
              nextEvent.subscribers.next().dispatchEvent(nextEvent.event);
            }
          }
        } finally {
          dispatching.remove();
          queue.remove();
        }
      }
    }

        printErrors(result);

        Iterator<Artifact> i = result.getArtifacts().iterator();
        assertEquals(n, i.next(), "n should be first");
        assertEquals(m, i.next(), "m should be second");

        // inverse order
        set = new LinkedHashSet<>();
        set.add(m);
        set.add(n);

     */
    public static AvPair get ( List<AvPair> pairs, int type ) {
        Iterator<AvPair> it = pairs.iterator();
        while ( it.hasNext() ) {
            AvPair p = it.next();
            if ( p.getType() == type ) {
                return p;
            }
        }
        return null;
    }


    /**
     * Remove all occurances of the given type
     *